Internal-combustion engine



Dec. 31, 1929. J. A. H. BARKEIJ INTERNAL co'uausnon ENGINE Filed Feb. 11, 1928 IIIIIIIIIII? Patented Dec. far, 1929 UNITED STA-IE5,

PATENT OFFICE 'J'EAN A. H. BARKEIJ', OF WASHINGTON, DISTRICT OF COLUMBIA mnrmar-connusrron Enema s'principles'set forth in my application Ser.

l52,708, in Fig. 36 together with'the description thereof on pages 4 and '5, to decrease the combustion space, for the turbulence principle set forth in the Patent No. 1,474,003 to H. R. Ricardo, by \placing the valves in inverted position above, and overlapping the cylinder bore; thereby decreasing the horizontal section of said chamber appreciably compared with 'a construction, in which said valves are constructed in upright position in the cylinder beside the cylinderbore, not overlapping same.

'It is well known that internal combustion enginesprovided with a turbulenceor so- "called Ricardo-head are harshin operation and are more or less subject-to detonation, piston slap and lubrication troubles on accountof the sudden sideway pressure of the explosion on the piston.

The soca'lled semi-Ricardo head provides an additional explosion space in the cylinderhead above the piston and improves aforesaid disadvantages appreciably, but looses to a great extent the desirable turbulencein the cylinderhead on account of the absence-of a throatbe twee'n the cylinderbore and cylinderheadcand secondly on account of the absence of the squeezing eifect between the lower side of the head and the piston top. v J It is the purpose of this invention to-'com-' bine the advantages of both types without its disadvantages by forming a turbulence and explosion chamber in the cylinderhead and an additional explosion chamber inthe cylinder. e a

The second object is to protect the top of the piston against the .heat of the explosion and to decrease its working temperature, thereby decreasing the danger of detonation, the center of the piston being the hottest place in the explosion space with the exception of the exhaust valve.

The third object is to obtain said advantages in an explosionchamber composed of more than two adjoining chambers. Its

Applicationfiled February 11, 1928. Serial No. 253,594.

'fourthobject is to combine said advantages with any position of the valves, located in the cylinder, or in the cylinderhead, or in both.

My fifth object 1s to make the throat be-- tween the explosion space in'the head and" the cylinderbore of a crosssection substaniti'any greater han the effective inlet valve port area and greater than the area of the intet valve, but smaller than halfthe-cylinderore. My sixth object is nearer theexhaust valve than the inletvalve for reasons to be explained here below. Fig; 1 is vertical section through an L-head cylinder, cylinder-head and piston, showing an explosion space in the head and partially in the cylinder, as will be explained here be- Fig. 2 is a horizontal section through Fig. 1 through the undersurface of the head and through the cylinderboreat its upper end to show the relative position of the'throat,

valves, sparkplug, and formof combustion chamber.- a

Fig. '3 is a vertical section through a valvein-head cylinderhead, a cylinderbore, showing the valves both overlapping the cylinderbore partially. J

Fig.

4 1s a through horizontal sect-ion of Fig. 3 the undersurface of the headand through the plane where the valves and spark I plug are located. v

Fig. 5 is a horizontal section through a siinilar section exhaust valve is in. upright position beside the cylinderbore and the inlet valve in which however the in inverted position overlapping said cylinderbore for reasons to be explained ,here-.

after. vThe throat has a section different from that shown in Fig. 4" and more or less conformto the position of the inlet and exhaust valves. The sparkplug is placed near the exhaust valve and another plug, (optionally), if so desired to allow a higher compression ratio than without it, for reasons to be piston top surface.

Fig. 6 is a vertical section through an L plication No. 238,587 of Dec. 8, 1927, in which explained hereafter, near the center of the I to. place the sparkplug the upper part of the cylinderbore or rather space above said cylinderbore is divided in two passages on either side of an intermediate wall or a depression of the cylinderhead reentering the cylinderbore.

F ig.'7 is a horizontalsection through Fig. 6, through the upper end of the cylinderbore and depression, forming part of the cylinderhead,'showing further the relative position of valves and sparkplug.

Fig. 8 is a vertical section of a similar arrangement as shown in Fig. 7, applied on an F -head construction, in which the inlet valve is shown in the head in inverted position overlapping the-cylinderbore, the exhaust valve in the cylinder in upright position, as already shown in horizontal section in Fig. 5.

Fig. 9 is a horizontal section of Fig. 8 through the upper part of the cylinderbore, showing further the relative position of the throat, valves and spa'rkplug near the exhaust valve, as shown in Fig. 5.

It is seen that-in all combustion chambers shown the longitudinal axis of the chamber height of the combustion chamber.

and thetransverse axis thereof, per endicular to the first axls, are longer tian the In Figs.

1, 2 in a special L-head formation these axes have lengths, which approach each other, in Figs. 3, 4 in a special valve-in-head formation the longitudinal axis is positively greater than the transverse axis, equally in Fig, 5.

In Figs. 6, 7 the same condition obtains again for a special L-head formation, and in Figs. 89 in a special F-head formation this conditionobtains also, only in varying degrees.

In the'first form of Figs. 1 and 2, the L-head construction, the longitudinal axis runs through the axes of the'two valves, parallel to the cylinderaxis. Thev transverse axis, perpendicular ,to the first axis, runs midway the axes of the valves through the cylinderaxis.

- area of the inlet valve.

In the third form of Fig. 5,511 F-head C011- struction, the longitudinal axis runs through the axes of both valves and through the cylin deraxis. This axis runs clear across the cylinderbore and is substantially longer-than the same .two previous ones. The transverse axis, perpendicular to the first, irunsthrough one of the axes of the two valves, parallel to the axis of the cylinder and is smaller than said through the axis of only one valve through the restricted passages 11 and 11*. This depends upon the'lengthofthe central depression 13, whether it extends from one side of the cylinderwall t0 the other side thereof. The transverse axis may run resp. to the first axis, perpendicularly thereon, through the same resp. axes or parallel thereto. The longitudinal axis is considered always to be the longest, the transverse axis, the Widthaxis the shortest. In the fifth form the F-head construction Figs. 8 and 9, the longitudinal axis runs through the axes of both valves and the cylinderaxis. It may run however parallel to these three axes, through the middle of the two restricted passages 11 and 11 approximately, depending again upon the length of the central depression 13. The

transverse, width-axis runs through one of the axes of the valves, or midway between the two, parallel to the cylinderaxis', and perpendicular to the longitudinal axis, where this maybe, one or two axes as explained.

In all five cases the transverse and longitudinal axes are greater than the height of the combustion chamber, especially the longitudinal axis. 1

Figs. 15 show one type of the species, having two adjoining combustion spaces, one in the head andone in the cylinder.

Figs. 69 show another type of the species, having more than two adjoining combustion slpaces, one in the head,.the others in the cylinc er.

In all figures, 1 is the cylinderhead, 2 the cylinder, 3the piston, 4 the wristpin, 5 the connecting rod, 6 the exhaust valve stem,'7 the exhaust valve passage in the cylinder, 8 the sparkplug. v

p In the first type, shown in Fig. 1, the explosion space in the cylinderhead can be divided into a space 9 over the valves and a space 10 over the cylinderbore. The second space 11 is in the cylinder, between the cylinder and the cylinderhead, which may extend into the cylinderbore as shown; The cylindrical space 12 between the head and the piston is as small as mechanical considerations allow or nearly so. If the ,piston approaches the head very close, approximately within of an inch, the turbulence will be violent, due to the squeezing effect of piston and head. It is I however dangerous to produce too much turbulence as this might even cause, instead of prevent, detonation. For that reason it is advisable to increase said distance to a' little sure upon the entire surface of-the piston, to

prevent the piston 0 rock. or slap in the cyliiiderbore at the -m oment of explosion.

This increase of distance can be effected of course equally when said cylinderhead does not reenter the head, as shown in Fig. 3 and 4,. and this space may be even in the head, if it is very small, without eliminating the throat and its effects. It maybe even partially in the head, partially in the cylinder;

between head elled by the piston before it reaches its top again provided, thefdistance and pistonin top position is decidedly more than that proposed in the Patent 1,474,003 to H. R. Ricardo, and decidedly less; than that shown and roposcd (in proportion to draw- K ing) in the atent No. 1,537,775 to I. F. Kelly in which a throat is entirely absent between the cylindei'bore and the. explosion space in the head. The distance in said patent is further so great thatthe squeezing effect between piston'and head is practically absent and itis the purpose of this application to retain said effect to a certain extent'acquiring thereby simultaneously the advantage of an explosion pressure on the entire surface of said piston. -The,piston,' after the inlet valve is closed, comes 'up and forces the gas during the entire compression period from the space 15 swept by the piston, through the additional explo-- sion spacell, forming more or less a throat,

into the space 10 and 9 in. the cylinderhead. During the last distance of piston-travel the gas is trapped between the" lower end 13 of the head and-the top.- 14 of-the piston and causes an additional turbulence. The explosion force from the spark plug cannot hit.

the piston top' immediately in case the head protrudsinto. the cylinder but has to make a double curve, which'is probably responsible for the absence of harsh action and detonation tendency; -If the. space 12 is increased a little beyond .the' mechanical minium of about less than g of an inch, the squeezing efiect between piston and head together with said 11 in thecylinder.

. throat will still create enough turbulence in the'space 9 to increase the flame propagation. Fig. 2 shows atop view cross section of- Fig. 1,-showing the explosion spaces 9, 10 in the cylinder'head an'd the reentrant portion 13 of the head 1 and additional explosion space InFig. 3 by raising-the lower end 13 of the head to a'practically flush-position with the top of the cylinder, the space 12, which was in one variation or 'modificationof. the type of 'Fig. 1 negligible-on account of the small height, is mereased to a full cylindrical, ad-

ditional, explosion space in the cylinder and the former additional explosion space 11 is reduced toa mere throat' between' the explosion space in the head and the explosion space in the cylinder. 'It resembles thereby the semi-Ricardo head construction, but with this important difference that in the latter the throat is eliminated and thereby also the turbulence-creating-action during the entire. com ression period. During the explosion, the orce of t e sudden pressure is apprecia- -.b1y decreased by this throat, resulting in'a .more gradual expansion. However in this type. as in the semi-Ricardo type t-he'squeez inglaction between head and piston is lost, but on account of the retained turbulence ac.- tion of the throat it is not lost entirely and v especially not during the last distance travposition. 'The amount of this additional tur bulence is due to the distance which remains between. the piston in its top position and the '7 still more, but this is not absolute necessary.

As shown in Figs. 3-5 this arrangement is very adaptable for a construction in which at least one of the valves, by preference the inlet valve, isplaced in the eylinderhead instead of in the cylinder adjacent to the exhaust valve, In Figs. 3 and 4 both valves are shown in the head, in Fig. 5 only the inlet valve 17 is shown in the head.

Comparing Fig. 4 with Fig. 2 it can be seen that the space 9 in the cylinderhead is considerably decreased compared with the same space in F ig 2. This allows the construction of the additional cylindrical explosion space 12 without constructing the spaces 9 and 10 in the head too shallow or without increasing the stroke abnormally. The spark plug is placed in a horizontal position to obtain the maximum benefit of the softeningeffeet of the throat 11 on the explosion. If this plug is placed to the left of the inlet valve 17 above said throat, the. explosion would be much harsher. Consequently the throat and spark plugposition together soften the explosion,'not the position of the plug only,

vor the throat only. .Another factor enters here affecting the specific position of sparkplug and exhaust valve. I found that the position of thesparkplug in relation to the position of the exhaust valve is as important as i the position thereof relative to the throat and its size. Itis possible to give. a good and sound explanation to this particular phenomenon. The 'sparkplug ignites the. gas in the neighborhood thereof, a region of pressure is produced and this region drives in front of it the gases, which did not yet have the ,.-time to be ignited and to combust. These gases will be compressed away from the sparkplug, if only one is employed. If this plug (onplugs) is located near the inlet valve, which is much cooler than the exhaust valve (where it may be located) the unburned "gases are compressed towards the exhaust Valve. What happens? The gases having there during a small fraction of a second, a high pressure, will detonate, being raised in temperature not only by the increased pressure, but also by the radiating heat from the hot exhaust valve. Reversely if the gases are ignitedin the neighborhood of the exhaust valve, the unburnt gases are compressed towards the cooler regions of the combustion" chamber and the unburnt gases there can only detonate on account of the increase in temperaturedue to the increase of temperature, but

minus the tem erature given off to the cooler walls in the neighborhood of said inlet valve. Undoubtedly some truth must be in this theory, as it is possible in certain combustion chambers to. increase the compression aboutone atmosphere, without being bothered by detonation more than with a lower compression rate and the sparkplug near the inlet valve. It has been steadfast practice, for so long as internal combustion engines working with a mixture and a sparkplug are made, to place the latter near the ir rlet valveto insure regular, firingwithout missing. This practice is reversed here. In some cases, if two sparkplugs are used, one may be as closeto the inlet valve as to the exhaust valve, butthey may be placed both near the exhaust valve.-

However the first-practice will already pre- 'vent detonation with certain compression ratios, as the gases unburnt have no time to be ignited and todetonate on account of the ra:

diation of heat from the exhaust valve. In

- other cases, it may be advisable toplace the second plug near the center of the top surface of the piston to prevent the unburnt gases'from being compressed towards the other hot spot in the combustion chamber. This practice is shown in Fig. 5 and will be discussed in connection therewith.

' 'In Fig. -5 it is shown that the throat 11 can be increased across the cylinder bore, as shown at 13 in Figs. l and 3, and an additional plug 8 can be placed opposite the plug .8 at the other end of the explosion space in the cylinderhead. According to-the theory just explained, the center of the piston in this ar-' rangement is exposed to the explosion-confpression space and the unburnt gases will be compressed thereagainst, away from the sparkplug near the exhaust Valve, at 8 and 16 resp. To suppress this tendency to detonation at certain pressures, it"is advisable to place a second plug, 8=, firing simultaneously with the other plug 8, at the other end of the longitudinal axis of said combustion chamber.- It is not absolutely necessary to use two sparkplugs, but the application thereof at the designated places will, allow a higher compression without a serious tendency to detonation. The explosionchamber is shown here considerably long and extends to the other side of the cylinderbore. The decreased space 9 in the head will allow this additional volume .without transgressing the volume necessary for an adequate compression.

Figs. 6-9 show the other types of the species and are modifications of the arrangement shown in my application No. 238,587 of-Dec. 8, 1927. In said application the underside of the depression 13 of the head is flush withthe flat surface of the cylinderbloclc Here this depression is further lowered into the cylinderbore, thereby obtaining'the same advantages for this type. In Figs. 6 and 7, the depression 13 divides the space in the .cylinderhead in three spaces, one 9 above the valves,

and two spaces 10 and 10 over the cylinder.

These two latter spaces-adjoin the additional explosion spaces 11 and 11 in the cylinder.

efl'ect ofa balanced pressure on the piston is however in this arrangement, as that shown in Figs.'5, 6 and 7, already'accomplished by the equal areas on both ides of a plane through the cylinderaxis iierp endicularto the piston pin. In Fig. 5 these areas differ only in form from those of Figs. 6 and 7 and those of Figs. 8 and 9. These'a 'eas may be located on both sides of a plane hrough the axis of the piston pin and axis of cylinder,

'ormay be located on both sides of a plane perpendicular thereto. 1 t

In Figs. 8 and 9 the space 9 in the head is again decreased by the position of both valves, or only one, by preference the inletyalve, in the cylinderhead. An additional cylindrical explosion space 12 in the cylindercan be applied without making the chamber in the head too shallow. The spaces.

or throats'lO and 10 cause a flow in opposite direction in the space 9 as shown by arrows in Fig. 7. If the inlet valve is placedin the cylinderhead and partially overlapping the cylinderbore to facilitate the flow of the gas, the depression 13 has to be decreased as shown in Fig. 9, thereby forming" an additional throat 10", from which an additional flow of gas will hit the flow in opposite directions, from the throats 10 and 10), in the middle during the I entire compression period. If the piston ,1 comes again close to the head this turbulence will be increasedat the very last moment by the squeezing efl'ect between head and piston. If the piston does not approach the head very close the turbulence caused by the throats erence horizontally toobtain the bene the'softening effects oftthe throats on the only have to increase the speed of the flame explosion. The single sparkplug is placed near the exhaust valve. The. center of the piston is already protected and shielded by the. depression 13 of the head. Two sparkand larger than plugs could be used. also here, one in hori- .zontal\position as shown inv Fig. 9, and one in vertical position above said exhaust valve as shown in Fig. 1. They both may be placed in vertical position above or near the passages l0 and 10 as already shown in said applica{ tion No. 238,587. Finally attention is drawn to the fact, that if the throat has a greater. area, the squeezing effect between piston and headdecreases, and also the turbulence effect solely due to the swirling of the mixturethrough said restricted passageduring the entire compression period. On'the other hand the throat cannot be made too narrow as the/ volumetric eflic'ien'cy would be aifected too much. For that reason, if the piston does not approach the head as close as possible (let us say anything mofe than of an inch) the ratio between valve and cylinderbore should be made very accurate after results of experiments. In general, said area of the throat should not be less than half the cross-section of the cylinderbore. The throat will consequently have an area less than half of, the cylinderbore the inlet valve port area. The area of the exhaust port less than that of the inlet valve,'.but this area is notvery relevant in this 'matter,

as the volumetric efliciency would be already a maximum in view of the inlet valve, unless I one of them is placed in'a more favorable poSiboth valves in Figs.

tion above the cylinderbore, as is shown for 3 and 4, and for the inlet valve in Figs. 5, 8 and 9.

- Finally it is pointed out thatthe distancebetween piston in top position and the underside of said head should not be more than about of an inch, otherwise the squeezing efl'ectjwill be so little as tohave little efl'ect on the acceler ation of the fl ame, due to this turbulence.

The throat j would ;still produce a certain.

amount oi turbulence during the-entire com of I the area of throat and inlet isiusually explosive type operating on a four-stroke pression period, but the last flip dueto the squeezing effect is highly im ortant, more so than the turbulencedue to t e throat only. It is understood that .the undersurface. of the head with central depression,as shown in the last Figs. 6-9, canbe .so constructed as shown in Fig'. 3, that said undersurface is:

flush with the upper rim of the cylinderbore.

principle may be applied withthe proposed constructions and forms of combustion chambers, without deviating from the spirit of. this application. The fuel-fluid may be then injected mechanically, with or without air,

in the cylinder. I; claim: I

1. In an internal combustion engine, in

combination, a cylinder, a piston'rec1procat-. ing therein, a cylinder-head entering said cylinder, said cylinderhead being formed with a combustion chamber therein, which liespartially over said cylinderbore, a throat formed between the cylinderwall and the head by whichsaid combustionchamber communicates with the space swept by. saidpiston inv "said how, saidth'rdat having a crosssection at least equal-"to the area of the inlet port" communicating withrsaid combustion chamher,- and controlled' byra poppet valve, an exhaust port controlled by a' pop e't valve in saigd combustion chamber, spar lxignition mean in said combustion chamber,

. 2. The combination of claim 1 in which said entering part-of the head is acentral depression from said "head; forming thereby two restricted passages at opposite sides of said depression and'opposite'sides of the cylinder- 'bore.

3. The combination of claim 1 in which said throat has an area substantialiyin excess of the area of said inlet valve.

4. The combination of claim spark ignition means areslibstantially closer to said exhaust valve than to said inlet valve.

5. An internal combustion .engine of the cycle, in combination; moylinder, a piston,

reciprocating. therein,a cylinder head entering said cylinder a combustion chamber in said cylinderhead, lying partially nover said bore, containing sparkigmtionmeans and any {said entering & cylihderhead forming with said cylinderbore j having an axisparallel, to the cylinderbore, having a length, said-- combustion chamber in said head communiinlet and an exhaust valve,

a throat, said throat eating with the cylinderbore through said im which said throat with a long1tudinal axis, perpendicu- ,7

.lar to its diameter. r 6. The combinatlon of c1a1m'5 1n wh1chf said piston approaches said 'undersurface ofeaid head with approximately a minimum mechanical clearance. v

7 The combination of claim in which said piston approaches said undersurface of said 5 head with a little more than mechanical clearance so that an additional explosion chamberis formed between said combustion chamher in the piston.

8. In an internal combustion engine, in

head and the space swept by said combination, a cylinder, a piston reciprocatring therein, a cylinderhead entering said cylinder, saidcylinderhead being formed with a combustion chamber" therein, which lies partially over said cylinder bore, an additional combustion chamber being formed between the piston and head, a throat formed ,between the-cylinderwall and. the head by which the'two chambers communicate, said L throat being approximately equal'to the area of the .inlet port and less thanthe crosssection of the cylinderbore, and sparkignition means in said combustion chamber.

9. In anunternal combustion engine, in

v combination, a cylinder, apiston reciprocating therein, a cylinderhead entering said cyl- -1nder, said cylinderhead being formed with a combustion chamber therein,'which lies par-.

tially over said cylinderbore, an additional combustion chamber being formed between the piston and the head, throats formed be v tween the cylinderwall and the head, by which the two chambers communicate, said throats bemggreater than the inlet-valve passage 7 f and less than the crosssection of the cylinder ibore, gas "inlet and outlet'passages for said i first chamber and ignition means in said j chamber.

' 10. The combination of cl. 8, in which at p 11. The combination of cl. 9, in which at least one of said valves is located in the cylmderhead to decrease the combustionspace in said head.

12..In'an internal combustion en combination, a cylinder, ing therein,

13. In an internal combustion engine as deleast one of said valves is located in said cyl-. iinderheadtodiminish the combustion space I; {in said head.

gine, ina piston reciprocata .cylinderh ead, said piston approachlng said cylinderhead atvmore than said cylinderhead being part of said scribed in cl. 12, in which said art of said head, entering the cylinderbore, orms a central' depression over the central part of said bore from one side to the other side thereof, forming thereby two passages between the space in saidcombustion chamber, containing v the valves, and the cylinderbore, one at either side of said depression and the cylinderbore.

14. In an internal combustion engine, in combination, a cylinder, a piston reciprocating therein, a-cylinderhead, said piston approaching said cylinderhead at more than a minimum distance, said cylinderhead being formed with a combustion head therein, lying partially over said cylinderbore, a throat formed between the-cylinderhead and the cylinderwall, said throat being substantially greater than the area of the inlet port and less than the cross-section of the cylinderbore, and sparkignition means in said combustion chamber, said chamber containing at least one valve in inverted position overlapping the cylinderbore to decreasethe area of the horizontal section of said chamber, said cylinderhead formin a depression over the center of the cylinder ore substantially. from one side to the opposite side of said bore, said depression forming at its undersurface two throats, at opposite sides of said depression with the upper surface of said cylinderbore.

15. In an internal combustion engine of the cycle, a cylinder, a piston reciprocating therein, a cylinderhead, a combustion chamber in said head lying partially over said cylinderbore, and containing the inlet and exhaust valves, an additional chamber being formed between the piston and head, a throat formed between the upper edge of the cylinder and the undersurface of the cylinderhead, by which the two chambers communicate, said throat being approximately equal to the area of the inlet port and less than the crosssection explosive type, operating on the fourstroke of the cylinderbore, sparkignition means in said combustion chamber, said throat beingv formed by a part of said head, entering said cylinder bore. v v

, 16. In an internal combustion engine; of the explosive type, operating on the fourstr'oke cycle, a cylinder, a iston reciprocating therein, a cylinderhea a combustion chamberin said head lying partially over said cylinderbore and containing the inlet and exhaust valves, an additional combustion chamber being formed between the piston and the head,

athroat formed between the upper edge. of the cylinder and the undersurface of the cylinderhead, bywhich the two chambers communicate,- said throat being approximately equal. to the area of the inlet port and less than thecnosssection of the cylinderbore, sparkignition means in saidcombustionchamber, said throat composed, of two re'strlcted pas-- sages, oneat either side of a, central depres- ,SIOII in said head, said restricted passages I formed by the .undersurface of'said head and the upper part .ofthe cylinderbore;

17 In an internal combustion engine of the explosive type operating on the fourstroke cycle, a cylinder, a piston reciprocating therein, a cylinderhead,-a combustion chamber in said headlying partially over said clyinderbore and containing 'the inlet and exhaust valves, an additional combustion chamber being formed between thev piston and the I head, a throat formed between the upper edge of the cylinder and the under surface of 1 the head, by which the -two chambers communicate, said throat I being approximately equal to the area of the 'inletport and less I than the crosssectionof the cylinderbore, sparkignition means in said/combustion chamber, saidthroat composed of two restricted passages, one at either side of a central depression in said" head, of which ,the undersurface is approximately flush with the ;upper edge of the cylinderbore, said restricted passages formed by the edges of said depression and the cylinder-bore.

18, The combinationlof cl. 15, in which said throat is formed at opposite sidesof a central depression of said head enterin said cylinderbore, said, throat composed 0 two restricted passagesbetween said depression and said cylinderbore;

- '19. In an internal combustion engine, in

.v combination, a cylinder',a (piston reciprocatingtherein, a cylinderhea proaching said cylinderhead at more than a minimum distance, said cylinderhead being "formed w th a combustion chamber therein,

:lyingpartially over said cylinderbore, a

. throat formed between the cylinderhead and the cylinder'wall, said throat being .substan- ."fan d' less than the crosssection of the oyl-, lnderbore and sparkignition means in said tiallygreater than the area of the inlet port conibustion chambexg'said chamber contain a said piston and the undersurfaceof said cyling at least one valve in inverted position,- above the cyhnderbore to decrease the area of the hor zontal section of-said chamber, an.

additional chamber being" formed between inderhead, separated from said combustion chamber in the head by said throat, said additionalchamber' having asubstantial volume compared with said first combustionchamber in the "head in view of the bore vand stroke of i said engine, said volume allowable on account of the overlapping position of One bf said valves over said cylinderbore, M g

20. In an internal combustion engine of the explosive type, operating onthe fourstroke cycle, a cylinder, 'a piston reciprocating therein, acylinderhead, a combustion chamber in said-head, lying partially over said cylinderbore and containing the inlet and exhaustvalves, an additional combustion chamber being formed between the piss ton and head, a throat. formed between the said piston apupper edge of the cylinder and the undersurface of the cylinderhead, by which the two' chambers communicate, said throat being approximately equal to the area of the inlet port and less than the crosssection of the cylinderbore, sparkignition means in said combustion chamber, at least one of said valves located in said'combustion chamber, above the cylinderbore, thereby decreasing the horizontal'crosssection of said chamber above the dividing line of the head and the cylinder, compared with said crosssection of a chamber having its valves besides the cylinder not overlapping said bore.

21. In an internal combustion engine, in combination, a cylinder, a piston recri rocating therein, a cylinderhead, a com ustion chamber in said head partially lying over said cylinderbore, an additional combustion chamber formed between the piston and head, a throat formed between the cylinderwall and the head by which the two chambers communicate, said throat being approximately equal to the area of the inlet port and less than the crosssection of the cylinderbore, ,an'

inlet and exhaust port controlled by poppet valves opening into said combustion chamber in the head, sparkignition means close to e said valves in said first combustion ch amber, one

of said valves overlapping said cylinderbore,

thereby decreasing the-horizontal section of;

said first chamber in the head, said throat further formed by two restricted passages between a depression in said head, lying over vthe center of sa'id'cylinderbore from one side to the other side thereof, and the cylin-derbore.

combination,.a cylinder, a piston reci rocating therein, a cylinderhead, a com ustion chamber in said head lying partially over said cylinderbore, an additional combustion chamber formed between the piston and head,

a throat formed between the cylinderwall and the head, by which the two chambers communicate,

to the area of the inlet port and less than the.-

said throat being approximately equal crosssection of the cylinderbore, an inlet and exhaust port controlled by poppet valves opening into said combustion chamber inrthe head, sparkignition means close to said valves in said first combustion chamber, one of said valves by preference the inlet valve overlapping said'bore, thereby decreasing the horizontal cross-section area of said first combustion chamber in said'head, said head entering 22. In an internal combustion chamber, in

said pcylinderbore with a central depression, 5

cylinderhead, a combustion tween the cylinder-Wall at its upper rim and said head at its undersurfaee, said throats being greater than the area of the inlet port and less than the cylinderbore, inlet and exhaust valves controlled by poppet valves opening into said combustion chamber in the head, ignition means in said combustion chamber in said head. I

' J, A. H. BARKEIJ. 

